It never hurts to take cues from nature when designing technology, and that's just what BioPower Systems did when engineering its bioSTREAM underwater generator. It's inspired by shark tails, using the shape in a fixed device that moves with the motion of the ocean. It reverses the use of the tail, with the water moving it rather than it moving in the water, but by anchoring it to a fixed point it allows it to align itself in any direction depending on how the flow is moving. No word on just how cost-effective generating energy this way would be, however. [BioPower Systems via PSFK]